I have a netbook/32gb. ($299)
I have a tablet PC/60gb. ($499)
Both also have USB ports, MicroSD slots, Webcams, mic ports, and can still run any app with the same functionality as the included iPad apps as well as 99% of the useful ones available from the app store. Both play more media formats as well. Both have stereo speakers (yes cheap ones like the single iPad speaker).
What I appreciate about the netbook and PC is their ability to be improved as my uses for them increase. I'd love an iPad too, but until they prove it can print to my networked printer and be memory upgraded after purchase it's not worth $499/16gb to me. My tablet can be used anywhere the ipad could. It doesn't need another PC or Mac for content though.
The iPad is clearly not for you, then.
If you need to play more media formats than the iPhone OS and iTunes have built-in, then the iPad is not for you.
If you need to print to networked printers, then the iPad is not for you.
If you're running RAM-intensive apps, then the iPad is not for you.
If you need mic ports and USB expansion, then the iPad is not for you.
If you're working with advanced Microsoft Office or other application document attachments, then the iPad is not for you.
The iPad is for people who want a simple browsing/eBook/email/iTunes-movie-playing/light-productivity slate with a no-brainer (and yes, vendor-locked) buy/install app store, simplified user interface and a one-app-at-a-time interface paradigm.
If you need more than that, the iPad isn't for you - and I don't think is marketed towards that demographic - and other solutions like standard netbooks or convertible tablet notebooks would be a better choice.
A very large percentage of the computer-using public likely falls into the iPad demographic. We don't see those people here because those people don't come here. If you're on these forums, odds are you're already too much of a power-user to be satisfied with an iPad.
Addendum:
Personally, I am buying an iPad. I want something small and light I can sit on the sofa with and browse the web, send a quick email, and browse the web. I also would like something to do some light productivity on (specifically, Keynote). I could do a large portion of what I want with an Android device. And I do; I use a Motorola Droid (rooted, with the DroidMod 1.0 ROM and WiFi tethering installed) as my primary cell phone. But I can't get Keynote for it, which is what I use when I give presentations. Docs To Go for Android won't allow me to build PowerPoint from scratch, so that's out (I have it for my phone). And there's no OpenOffice.org build for Android yet, so that's out, too. I figure the iPad will do about 75-80% of what I do on my laptop, but in a smaller, funner form-factor. When I need USB expansion or network printing, well, then I'll walk over to my desktop or laptop and finish the job. But I don't need to carry all that with me at all times. Like I said, the iPad will get most of it done for me, so I find it's worth the $499. Well, $699 in my case since I bought the 64GB version.
As for my wife, for whom I also ordered an iPad - well, she fits the above target market perfectly. She doesn't need any advanced capabilities - email and web browsing with the occasional Pages document is pretty much it. She doesn't need to multitask and she needs a device that's simple to use and maintain. She has an iPhone and loves it. An iPad, she says, would be perfect for her (she's watched all the videos and she's more excited for hers than I am for mine).
If my wife is any indication of Apple's target demographic, they'll sell a gazillion of them.